1. Technical Field
The present invention relates to liquid ejecting heads that eject liquid from a nozzle opening and liquid ejecting apparatuses, and particularly relates to ink jet recording heads that eject ink as a liquid and ink jet recording apparatuses.
2. Related Art
An ink jet recording head that includes a flow channel formation substrate in which a plurality of pressure generation chambers are formed along the lengthwise direction and piezoelectric actuators provided for the respective pressure generation chambers on one surface of the flow channel formation substrate, and that ejects ink droplets from respective nozzle openings by using displacement in the respective piezoelectric actuators to generate pressure inside the pressure generation chambers, exists as a representative example of a liquid ejecting head that ejects a liquid. Here, the nozzle openings are caused to correspond with respective pressure generation chambers, and are provided so as to pass through in the thickness direction thereof (for example, see JP-A-2006-212478 and JP-A-2009-233870). A nozzle plate is attached to the other surface of the flow channel formation substrate so as to seal an opening portion on the other sides of the pressure generation chambers. In other words, the nozzle plate is affixed directly to the other surface of the flow channel formation substrate.
However, the nozzle plate is a comparatively high-cost member, and is one cause of an increase in the cost of the ink jet recording head. Furthermore, although there are nozzle plates to which insulative water-repellent film is applied, doing so causes an even greater increase in costs.
In addition, the flow channel formation substrates are formed by first forming a plurality of flow channel formation substrates on a wafer for flow channel formation substrates, which are silicon single-crystal substrates, and then cutting out the flow channel formation substrates therefrom. Accordingly, it is vital to increase the yield of the flow channel formation substrates in order to achieve a reduction in the cost of the ink jet recording head. Accordingly, it is desirable to reduce the size of the flow channel formation substrates to the greatest extent possible.
However, in the ink jet recording head according to the past technique described above, a liquid holding portion that holds the ink supplied to the pressure generation chambers is also provided in the flow channel formation substrate, and thus there is a limit to the degree by which the size can be reduced; this poses a problem in that it interferes with the cost reduction.
It should be noted that these problems are not limited to ink jet recording heads that eject ink, and are also present in other liquid ejecting heads that eject liquids aside from ink.